1. Field of the Invention
The invention relates to an arrangement for assembling products in batches.
The invention relates more specifically to an arrangement for assembling a plurality of products in the form of batches, the arrangement being of the type in which the products are transported on at least one conveyor belt which runs in a longitudinal direction from an intake zone upstream to an exit zone downstream, at a specified speed known as the running speed, in which the products arrive with a specified upstream spacing between two products, and of the type which has a phasing device which is placed on the path of the products so as to form batches of at least two products.
2. Description of the Related Art
This type of arrangement is used in product packaging installations, for example in installations having a conveyor line which conveys the products to a box filling machine which stacks batches of products in packaging crates or boxes.
The conveyor line generally has a conveyor belt which is upstream of the box filling machine, and which transports the products, with a specified spacing between two consecutive products, to an assembly unit having a set of movable transport cells.
The assembly unit has a vacant cell opposite the belt, designed to receive a specified number of products which are to be stacked in the cell to form a batch.
When a batch has been formed in the cell, the cell is moved by one step to enable the assembly unit to position a new vacant cell opposite the belt.
The cells thus move progressively, one step at a time, enabling the batches of products to be conveyed to the box filling machine.
To facilitate and accelerate the filling of the cells, there is a known way of forming the batches of products upstream of the assembly unit, by means of a device called a phasing device.
There is a known way of making the phasing device in the form of a plurality of successive conveyor belts, called timing belts, which operate at different running speeds.
In this type of phasing device, the products are delivered, by a first conveyor belt, onto an upstream acceleration belt operating at a running speed greater than that of the first belt.
The upstream belt conveys the products to an intermediate deceleration belt.
The products are pressed against the intermediate belt and retained thereon by means of a suction device located below.
The intermediate belt shifts each product progressively forward until a batch has been formed on the intermediate belt.
When the batch of products has been formed, the running speed of the intermediate belt increases in order to transfer the batch to a downstream belt which operates at a running speed similar to that of the upstream belt.
This type of phasing device is not entirely satisfactory, since it requires the use of a plurality of conveyor belts placed end to end, giving rise to problems in respect of the overall longitudinal dimension of the installation.
The control of the speed of the different conveyor belts and the lengths of these belts are calculated for a given type of product and batch. It is therefore necessary to set up a new phasing device when the length of the products, or the number of products per batch, is changed.
Furthermore, the suction device does not operate for certain types of products, and this limits the field of application of this phasing device.
Additionally, because of its design, this phasing device cannot be used for processing products at very high speeds, for example at speeds of more than 900 products per minute.